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# Python for RiveScript Go
It'd be nice if rivescript-go were able to parse and run Python object macros for RiveScript bots, by using the [Python C API](https://docs.python.org/3/c-api/index.html).
There are two projects I found so far: [sbinet/go-python](https://github.com/sbinet/go-python) and [qur/gopy](https://github.com/qur/gopy). They both only support Python 2 so far, but that will work for now.
I did some experimenting and came up with the following Go code that demonstrates the key pieces of functionality needed: dynamically parse a Python function, call the function giving it an array of string arguments, and retrieve the result of the function as a Go string.
```go
package main
import (
"fmt"
"github.com/sbinet/go-python"
)
func init() {
err := python.Initialize()
if err != nil {
panic(err.Error())
}
}
func main() {
// The source code of the python function we wanna be able to call.
pycode := `
def test(rs, args):
print "Test works"
return "Forwards: {}\nBackwards: {}".format(
" ".join(args),
" ".join(args[::-1]),
)
`
// The []string to use as the 'args' param to `def test()`
args := StringList_ToPython("Hello", "world")
defer args.DecRef() // Always do this so Python can count references well.
// To load the function you can simply eval the code in the global scope:
python.PyRun_SimpleString(pycode)
// Get the main module's dictionary so we can get a reference to our
// function back out of it.
main_module := python.PyImport_AddModule("__main__")
main_dict := python.PyModule_GetDict(main_module)
test_function := python.PyDict_GetItemString(main_dict, "test")
// The tuple of (rs, args) arguments to pass to the function.
// This tuple is the *args in Python lingo.
test_args := python.PyTuple_New(2)
python.PyTuple_SetItem(test_args, 0, python.Py_None)
python.PyTuple_SetItem(test_args, 1, StringList_ToPython("Hello", "world"))
// Call the actual Python function now. Functions return a *PyObject, and
// we can cast it back to a string.
returned := test_function.CallObject(test_args)
result := python.PyString_AsString(returned)
// Print the result of the function.
fmt.Println("Result:", result)
}
// StringList_ToPython is a helper function that simply converts a Go []string
// into a Python List of the same length with the same contents.
func StringList_ToPython(items... string) *python.PyObject {
list := python.PyList_New(len(items))
for i, item := range items {
python.PyList_SetItem(list, i, python.PyString_FromString(item))
}
return list
}
```